The Frost Line

Ceres is a dwarf planet covered by a dusty regolith (outer soil layer). No one is quite sure what is beneath that dust. The answer to the question may help astronomers to understand something about the early solar system.

Why It Matters

The placements of the planets in our solar system led scientists to an idea.

The hot sun drove off the ices and gases when the inner planets formed. Further out in the solar system, cooler temperatures allowed gases and ices to exist.

The result is that the rocky planets are near the sun and the gas giants are further out.